add MUMXPC_dean_stiel

HugoMVale · Dec 9, 2023 · 4166a7c · 4166a7c
1 parent 18ceab6
commit 4166a7c
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Showing 2 changed files with 56 additions and 4 deletions.
diff --git a/src/polykin/properties/viscosity/vapor.py b/src/polykin/properties/viscosity/vapor.py
@@ -5,12 +5,15 @@
 from polykin.types import FloatVector, FloatOrArray
 
 import numpy as np
+from math import sqrt
 from scipy.constants import R
 
 __all__ = ['MUVMX2_herning',
            'MUVPC_jossi',
+           'MUMXPC_dean_stiel',
            'MUV_lucas',
-           'MUVMX_lucas']
+           'MUVMX_lucas'
+           ]
 
 # %% Mixing rules
 
@@ -96,6 +99,29 @@ def MUVPC_jossi(rhor: float,
     return (a**4 - 1)/xi
 
 
+def MUMXPC_dean_stiel(V: float,
+                      y: FloatVector,
+                      M: FloatVector,
+                      Tc: FloatVector,
+                      Pc: FloatVector,
+                      Zc: FloatVector,
+                      ) -> float:
+
+    M_mix = np.dot(y, M)
+    Tc_mix = np.dot(y, Tc)
+    Zc_mix = np.dot(y, Zc)
+    Vc = Zc*R*Tc/Pc
+    Vc_mix = np.dot(y, Vc)
+    Pc_mix = Zc_mix*R*Tc_mix/Vc_mix
+
+    rhor = Vc_mix/V
+    # xi = 1e3*Tc_mix**(1/6)/(sqrt(M_mix*1e3)*(Pc_mix/101325)**(2/3))
+    xi = 6.87e4*Tc_mix**(1/6)/(sqrt(M_mix)*(Pc_mix)**(2/3))
+    a = 10.8e-5*(np.exp(1.439*rhor) - np.exp(-1.111*rhor**1.858))
+
+    return a/xi
+
+
 # %% Estimation methods
 
 def MUV_lucas(T: float,

diff --git a/tests/properties/test_viscosity.py b/tests/properties/test_viscosity.py
@@ -2,10 +2,12 @@
 #
 # Copyright Hugo Vale 2023
 
-from polykin.properties.viscosity import MUVMX2_herning, MUVPC_jossi, \
-    MUV_lucas, MUVMX_lucas, MULMX2_perry
+from polykin.properties.viscosity import MUVMX2_herning, MULMX2_perry, \
+    MUVPC_jossi, MUMXPC_dean_stiel, \
+    MUV_lucas, MUVMX_lucas
 
 import numpy as np
+from scipy.constants import R
 
 
 def test_MUVMX2_herning():
@@ -25,7 +27,31 @@ def test_MUVPC_jossi():
     rhor = 263/243.8
     M = 58.12e-3
     mu_pc = MUVPC_jossi(rhor, M, Tc, Pc)
-    assert np.isclose(mu_pc, (273-120)*1e-7, rtol=2e-2)
+    assert np.isclose(mu_pc, 1.53e-5, rtol=2e-2)
+
+
+def test_MUMXPC_dean_stiel_1():
+    "Example 9-11, p. 425"
+    y = np.array([1.])
+    M = np.array([58.12e-3])
+    Tc = np.array([408.2])
+    Pc = np.array([36.5e5])
+    Zc = Pc*263e-6/(R*Tc)
+    V = 243.8e-6
+    mu_pc = MUMXPC_dean_stiel(V, y, M, Tc, Pc, Zc)
+    assert np.isclose(mu_pc, 1.53e-5, rtol=0.1)
+
+
+def test_MUMXPC_dean_stiel_2():
+    "Example 23, p. 2-363, Perry's"
+    y = np.array([0.6, 0.4])
+    M = np.array([16.04e-3, 44.10e-3])
+    Tc = np.array([-110.4, 96.7]) + 273.15
+    Pc = np.array([4.593e6, 4.246e6])
+    Zc = np.array([0.288, 0.281])
+    V = 1/3.55e3
+    mu_pc = MUMXPC_dean_stiel(V, y, M, Tc, Pc, Zc)
+    assert np.isclose(mu_pc, 3.7e-6, rtol=0.1)
 
 
 def test_MUV_lucas():